Xserve RAID Technology Overview October 2004

Transcription

1 Technology Overview October 2004

2 2 Contents Page 3 Page 4 Page 7 Page 12 Page 14 Page 18 Page 24 Page 26 Page 28 Introduction Product Overview Key Features High-Availability Design RAID Basics RAID Techniques RAID Levels Deploying Applications Management and Monitoring Setting Up and Managing Arrays Monitoring Systems Managing Volumes Managing Volumes with Xsan System Architecture Drive Technology and Capacity Passive Midplane Data Path RAID Controllers Fibre Channel Interconnect High-Availability Features Service, Support, and Training Options Purchasing Information Technical Specifications

3 3 Introduction Features at a Glance Larger, 400GB drive modules for even more capacity up to 5.6TB of storage per 14-drive system 1 Industry-standard SFP (Small Form-factor Pluggable) connectors for additional deployment flexibility in optical or copper infrastructures Advanced capabilities such as LUN slicing and online expansion Certification of compatibility by leading storage infrastructure vendors Qualification for use in Linux, Windows, NetWare, and mixed-platform environments Last year, Apple introduced, a high-availability, high-performance storage solution at a groundbreaking price. With massive capacity and industry-leading remote management capabilities in a compact 3U enclosure, put powerful RAID features within easy reach an ideal solution for near-line and disk-to-disk storage, as well as for protecting business- and mission-critical data. The new builds on the success of its predecessor with even more capacity, industry-standard SFP connectors, and advanced management functions. Apple has worked with leading storage infrastructure vendors to certify for integration with existing Fibre Channel hardware and data management solutions. What s more, is now qualified for use in Linux, Windows, NetWare, and mixed-platform environments. 2 At the heart of is an innovative Apple-engineered architecture, with 14 high-performance drive channels, dual independent RAID controllers, and a dual 2Gb Fibre Channel host interface. Together they provide up to 5.6TB of storage 1 that can grow as you go and throughput of up to 400 megabytes per second. 3 Robust monitoring and notification features and hot-swappable components keep your data online and available. And with intuitive tools for quick configuration of protected storage volumes, this revolutionary RAID solution delivers ease of use that could come only from Apple. High-performance, high-availability storage has never been so affordable. With a low price, simplified administration, easy serviceability, and flexible deployment options, is designed to protect your organization s bottom line, as well as your digital assets.

4 4 Product Overview combines leading-edge storage technologies for massive capacity, fast performance, and superior data protection. Xserve G5 works seamlessly with Xserve G5, Apple s high-density 1U rackoptimized server. Equipped with single or dual PowerPC G5 processors, Xserve packs phenomenal power and a rich feature set into an affordable, easy-to-deploy system. Key Features is a cost-effective answer to the growing storage requirements of businesses and institutions everywhere. Its high-performance, high-availability features include: Massive storage. holds up to 14 hot-swappable Apple Drive Modules now with 5.6TB of total storage in a rack-optimized 3U enclosure. 1 Each 400GB hard drive connects to a dedicated Ultra ATA drive channel, eliminating a traditional source of bottlenecks and maximizing the 400MB/s Fibre Channel host connection. By adding more systems, you ll have virtually limitless expansion capabilities: A standard 42U rack can hold over 78TB of storage. 4 Advanced data protection. The high-availability architecture and dual independent RAID controllers support RAID levels 0, 1, 3, 5, and 0+1. also supports hybrid RAID levels 10, 30, and 50 when used in conjunction with host-based software RAID. High-availability design. To ensure availability of your critical data, is designed for nonstop operation. Redundant hot-swappable power and cooling modules allow the system to keep functioning even if one module fails. All the active components are modular, making it easy to replace them in seconds usually without any interruption of service and with no tools required. In the event of a failed drive, a global hot spare provides automatic rebuilding of data, without administrator intervention. 5 Fast data access. With sustained throughput of up to 380MB/s, the advanced Xserve RAID architecture delivers fast access to storage without compromising data integrity. 6 Dual independent RAID controllers provide protected storage with unprecedented performance. In fact, boasts a throughput at RAID level 5 that s fast enough to support real-time, 10-bit high-definition (HD) 1080i video editing. Intuitive management and monitoring tools. Sophisticated remote management capabilities dramatically simplify setup and monitoring of RAID storage. The Java-based RAID Admin application can build RAID sets on the fly, allowing administrators to bring protected storage online instantly, without waiting for initialization. RAID Admin also provides continuous feedback on system activity and health. If a problem is detected, the remote monitoring software automatically sends notification via or pager, so administrators can quickly identify problems and repair them without downtime or data loss. Comprehensive service and support. To ensure rapid issue resolution for your server and storage deployments, choose from a full range of AppleCare products designed to provide integrated expert support.

5 5 High-Availability Design The 3U enclosure is built for reliability, availability, and serviceability with high-quality, Apple-engineered construction. LEDs on the front panel provide continuous visual feedback on system status and activity levels; and 14 drive bays support hot-swapping of drive modules. The back panel features easy access to redundant RAID controllers and field-replaceable power, cooling, and battery modules, as well as connectivity to one or more host computers and up to two uninterruptible power supply (UPS) devices. Front View Apple Fibre Channel PCI-X Card connects to a host Xserve or Power Mac system using the dual-port 2Gb, 133MHz Apple Fibre Channel PCI-X Card (sold separately) with throughput of up to 400MB/s. 3 The Fibre Channel interconnect technology supports multiple application environments using point-to-point, loop, and fabric technologies Apple Drive Modules. holds up to 14 hot-swappable Apple Drive Modules. Each drive is on an independent channel to maximize data throughput and increase system reliability. LEDs on the front of each module indicate drive health and activity. System lock. A built-in lock secures the drive modules in the system. The remote monitoring application shows the status of enclosure security and can notify the administrator if someone unlocks it. Unit identifier. Duplicate system identifier buttons on the front and back of the system can be turned on manually or by using the remote monitoring software, making it easy to locate a particular in a rack with multiple devices. The buttons also illuminate if a system event occurs. Alarm silencer. In the event of a component failure, the alarm system is triggered; with a touch of this button, the alarm is silenced. The remote monitoring software provides detailed event information about the affected system and notifies the administrator via or pager. System status indicators. Indicator lights display status for power supplies, cooling modules, RAID controllers, and system temperature. System activity indicators. Forty-six blue LEDs provide at-a-glance activity levels for each host channel, and Fibre Channel indicators provide link status information.

6 6 Back View Convenient replacement modules Problem resolution is fast with AppleCare Service Parts Kits for (sold separately). Each kit has an Apple Drive Module, power supply module, cooling module, and RAID controller module RAID controller modules. Two independent storage processor units manage RAID functions, data transfers, and failure protection for each set of seven drives. The environment management coprocessor in each controller simplifies configuration and management of RAID sets. Serial ports. Standard DB-9 serial ports allow connection to UPS units for protection from brownout or over-voltage conditions. Ethernet ports. The 10/100BASE-T Ethernet interfaces allow you to manage, monitor, and diagnose systems over TCP/IP. Fibre Channel ports. Each RAID processor connects to the host system via a 2Gb Fibre Channel interface with throughput of up to 200MB/s per port. 3 Throughput is assured, which means bandwidth remains constant, even as more devices are added in a fabric configuration. Industry-standard SFP connectors support both optical and copper infrastructures. Optional batteries. Cache Backup Battery Modules can provide more than 72 hours of backup power to protect the integrity of data in the RAID controller cache during a power outage. Power supply modules. Either of the redundant, load-sharing power supplies can power should the other one fail. A failed power supply can be replaced in seconds without tools and without shutting down the system. Cooling modules. Redundant, hot-swappable cooling modules provide automatic front-to-rear cooling for rack environments.

7 7 RAID Basics Redundant array of independent disks, or RAID, is a grouping of multiple physical hard drives into an array, or RAID set, that appears to the host computer as a single logical storage unit. Use of RAID technology enables organizations to increase storage capacity while achieving levels of performance, reliability, and data protection not possible from a single hard drive. All drives in the array can operate simultaneously for dramatically faster overall throughput. RAID systems can also improve data availability and fault tolerance, because redundant data can be stored on multiple physical drives. Even in the event of a drive failure, the system can continue to operate without loss of data and with no interruption in service. Software versus hardware RAID RAID functionality can be implemented in hardware or software. Software RAID available in Mac OS X and Mac OS X Server enables drive striping and drive mirroring, whether for basic RAID 0 or RAID 1 configurations or for robust configurations using hybrid RAID levels 10, 30, or 50. Software RAID is not recommended for parity RAID levels, such as RAID 3 and 5, which involve compute-intensive calculations that can overtax the system processor. RAID Techniques RAID technology is based on three practices: striping to improve storage performance, and mirroring and parity to provide redundancy for increased data protection. Most RAID configurations, or RAID levels, combine these techniques to provide a balance of data protection and performance. Striping Increased performance in a set of multiple drives is accomplished by data striping. As the name implies, striping divides a logical drive into data blocks, or stripes, that are distributed across the array of physical drives. Data is then laid down according to the stripe paths, so that each file is spread across multiple drives. Striping a set of disks greatly improves overall storage performance because the drives operate in parallel. While one drive is writing or reading a data block, another is seeking the next block. Striping alone, known as RAID level 0, offers no data protection. Mirroring The simplest method of achieving data redundancy, mirroring involves writing identical copies of all data to a pair of physical drives. This results in very high data reliability: If one drive fails, the data is still available on the remaining disk drive. However, it also results in storage efficiency of only 50 percent, because two physical drives are required to create a protected storage volume with the equivalent capacity of a single drive. Mirroring alone is known as RAID level 1. Parity A more sophisticated method of creating redundancy, parity provides data protection for an array of drives without requiring complete duplication of the drive contents. Parity information can be used along with the data on the surviving drives to reconstruct the contents of a failed drive. The parity data can be stored on a dedicated drive, as in RAID 3, or distributed across an array of drives, as in RAID 5. In either case, parity provides much greater storage efficiency than mirroring up to 85 percent for a set of seven drives.

8 8 RAID Levels Each RAID level offers a unique balance of I/O performance, data protection, and storage efficiency. supports all popular RAID levels, so you can select the best configuration for your application and your budget. Comparison of RAID levels RAID level Minimum Storage Read Write Data number of efficiency performance performance redundancy drives required RAID 0 2 Highest Very high Highest No RAID 1 2 Low High Medium Yes RAID 3 3 High to very high Medium Medium Yes RAID 5 3 High to very high High High Yes RAID Low High High Yes RAID 10 4 Low High High Yes RAID 30 6 High to very high High High Yes RAID 50 6 High to very high Highest Very high Yes Each RAID level offers a unique balance of performance, data protection, and drive efficiency. The efficiency of parity RAID levels increases with the number of drives in an array. RAID 0: Striping RAID 0 distributes data evenly in horizontal stripes across an array of drives. While RAID 0 offers substantial speed enhancements, it provides no data protection: If one drive fails, all of its data is lost and all drives must be reformatted. RAID 0 provides the most efficient use of drive capacity, because no storage space is dedicated to redundant data or parity information. RAID 0 Stripe 1 Stripe 4 Stripe 7 Stripe 10 Stripe 2 Stripe 5 Stripe 8 Stripe 11 Stripe 3 Stripe 6 Stripe 9 Stripe 12 Disk 1 Disk 2 Disk 3 RAID 0, or drive striping, breaks a single file into data blocks and distributes it across two or more drives.

9 9 RAID 1: Mirroring RAID 1 creates a pair of mirrored drives with exactly the same data. It provides a high level of data availability and, by using both drives simultaneously, offers fast read performance. Write speeds are lower, however, because all data is written twice once to each drive. RAID 1 is also relatively expensive to deploy because it offers the poorest level of drive efficiency. RAID 1 Stripe 1 Stripe 2 Stripe 3 Stripe 4 = Stripe 1 Stripe 2 Stripe 3 Stripe 4 Disk 1 Disk 2 Mirrored drives in RAID 1 contain identical sets of data for total redundancy. RAID 3: Striping with parity RAID 3 stripes data across two or more drives and stores parity data on a dedicated drive. In the event of a disk failure, the redundant parity bits can be used to reconstruct data on any drive. RAID 3 offers fast read rates and high data availability, with greater storage efficiency than RAID 1. Write performance in RAID 3 is faster than in RAID 1, but not as fast as in RAID 5, because it depends on the availability of a separate parity drive. RAID 3 requires a minimum of three drives; using more drives results in faster performance and greater drive efficiency. RAID 3 Parity generation Stripe 1 Stripe 4 Stripe 7 Stripe 10 Stripe 2 Stripe 5 Stripe 8 Stripe 11 Stripe 3 Parity 1 3 Stripe 6 Parity 4 6 Stripe 9 Parity 7 9 Stripe 12 Parity Disk 1 Disk 2 Disk 3 Disk 4 RAID 3 stripes data across two or more drives and stores parity data on a dedicated drive.

10 10 RAID 5: Striping with distributed parity RAID 5 distributes both data and parity information across an array of drives one block at a time, with each drive operating independently. This enables maximum read performance when accessing large files and improves performance in a transaction-processing environment. Write performance is also improved because parity information is striped across the drives, removing the bottleneck of a single parity drive. RAID 5 is the most popular configuration for high-throughput protected storage. Like RAID 3, RAID 5 requires a minimum of three drives; using more drives provides faster performance and higher storage efficiency. RAID 5 Parity generation Stripe 1 Stripe 4 Stripe 7 Parity Stripe 2 Stripe 3 Parity 1 3 Stripe 5 Parity 4 6 Stripe 6 Parity 7 9 Stripe 10 Stripe 8 Stripe 11 Stripe 9 Stripe 12 Disk 1 Disk 2 Disk 3 Disk 4 RAID 5 distributes data and parity information across all the drives in an array. RAID 0+1: Striping over mirroring This hybrid RAID level is created by striping data across multiple pairs of mirrored drives. With, both striping and mirroring are set up in hardware, which means the array can run independently of the server processor. RAID 0+1 provides higher throughput with simpler setup than protected configurations that use software RAID for striping, such as RAID 10. RAID 0+1 Mirrored pair Striped pairs Mirrored pair Stripe 1 Stripe 1 Stripe 2 Stripe 2 Stripe 3 Stripe 5 = Stripe 3 Stripe 5 Stripe 4 Stripe 6 = Stripe 4 Stripe 6 Stripe 7 Stripe 7 Stripe 8 Stripe 8 Disk 1 Disk 2 Disk 3 Disk 4 offers a hardware RAID level 0+1, which mirrors drive pairs and then stripes data across the mirrored sets.

11 11 RAID 10, 30, and 50 Hybrid RAID levels 10, 30, and 50 use hardware RAID to create two or more sets in RAID 1, 3, or 5, and software RAID to stripe across the sets. This creates a single data volume with the best balance of performance and data protection. In the case of, you can combine all 14 drives for high performance at maximum capacity. RAID 50 RAID 5 set Striped sets RAID 5 set Parity generation Stripe 1 Stripe 2 Stripe 3 Parity 1 3 Parity generation Stripe 1 Stripe 2 Stripe 3 Parity 1 3 Stripe 4 Stripe 5 Parity 4 6 Stripe 6 Stripe 4 Stripe 5 Parity 4 6 Stripe 6 Stripe 7 Parity 7 9 Stripe 8 Stripe 9 Stripe 7 Parity 7 9 Stripe 8 Stripe 9 Parity Stripe 10 Stripe 11 Stripe 12 Parity Stripe 10 Stripe 11 Stripe 12 Disk 1 Disk 2 Disk 3 Disk 4 Disk 5 Disk 6 Disk 7 Disk 8 This RAID 50 configuration uses software RAID to stripe data across two RAID 5 sets, which are created using hardware RAID.

12 12 Deploying Exponential growth in the creation and distribution of digital content is driving demand for high-capacity storage solutions. Large databases, digital video footage, immense scientific data sets, and expanding archives of financial information and employee records require terabytes of storage. At the same time, data protection and near-instant data access are crucial to many organizations. In response to these pressing requirements, customers have been forced to make tradeoffs among data protection, performance, and capacity or spend hundreds of thousands of dollars on high-end storage solutions that combine these features. : A unique blend of features A robust feature set and highly flexible deployment options make it possible to use in a wide range of environments, including: Mission-critical data storage deployments, where zero downtime is paramount at virtually any cost Business-critical data storage deployments, which require high capacity and high availability at a reasonable cost Near-line archive deployments, which seek a balance of high capacity, scalability, and reasonable throughput at the lowest possible cost Rich media storage deployments, which require superfast throughput, data protection, large capacity, and a reasonable cost is a revolutionary storage product that eliminates the need for these tradeoffs. With massive capacity and high-availability features previously available only in much more expensive storage systems, offers unmatched versatility at an unprecedented price. What s more, it meets the most demanding performance requirements, delivering a sustained throughput of up to 380MB/s the highest of any RAID system in its class. 6 These robust capabilities make ideally suited for protecting mission- and business-critical data, yet it s affordable enough for nearline storage deployments and fast enough for media production environments. Comparison of storage solutions Apple Dell IBM HP Sun EMC AX100 DS4100 StorageWorks StorEdge MSA Capacity 5.6TB 3TB 3.5TB 3.5TB 3TB Size 3U 2U 3U 2U 2U Price* $12,999 $14,291 $16,765 $22,190 $36,995 Price per GB $2.32 $4.76 $4.79 $6.34 $12.33 * Based on prices published on manufacturers websites as of October 4, Configurations vary. Features are similar in class. Compared with leading storage products, offers the lowest cost per gigabyte. At the same time, it packs more gigabytes in less space up to 5.6TB in a 3U enclosure. 1 Applications Whether in all-apple or heterogeneous environments, can fit into existing storage networks or provide a foundation for new deployments. The industry-standard SFP-based Fibre Channel interface supports point-to-point, loop, and fabric topologies for integrating into Fibre Channel storage infrastructures. In addition, a platform-independent design and Java-based administrative tools make setup and monitoring easy from virtually any Internet-connected computer. Now certified by leading storage network manufacturers and qualified to work with popular operating systems, is a flexible solution for a full range of storage applications.

13 13 Third-party certifications Leading storage infrastructure vendors have certified for integration with existing Fibre Channel hardware and data management solutions, including: QLogic Brocade Emulex LSI Logic VERITAS ATTO Technology Candera Cisco In addition to Mac OS X and Mac OS X Server, has been qualified for use on these operating systems: Windows Server 2003 Windows 2000 Server Windows 2000 Professional Red Hat Enterprise Linux v2.1 and v3 Novell NetWare v5.x and v6.x SUSE Enterprise Server 9 Yellow Dog Linux v3 Primary storage for Mac, Windows, Linux, and NetWare servers With high-availability features such as redundant power and cooling, protected RAID storage, global drive hot sparing, and hot-swap components, delivers fast, reliable data access meeting the requirements of the most demanding businesscritical and mission-critical storage deployments. It also provides the capacity and deployment flexibility required for High Performance Computing (HPC) environments. At the same time, offers industry-leading capacity, up to 5.6TB, 1 and can support dozens of servers using advanced LUN slicing and mapping capabilities. Best of all, this outstanding feature set is available at a cost far below that of competing primary storage products. Network-attached storage (NAS) teams with Xserve G5, Apple s easy-to-deploy 1U server, to provide an affordable alternative to traditional network-attached storage (NAS) devices. Offering the compatibility of open standards and Apple s legendary manageability, this highperformance, high-capacity solution allows Mac, Windows, Linux, and NetWare clients to share terabytes of information with no per-user licensing fees. At the same time, has the flexibility to fit easily into existing mixed-platform storage area networks (SAN). Near-line and disk-to-disk archive offers outstanding value for near-line applications, while providing the ready data access required by many governmental regulations for and HR records. Fibre Channel connectivity provides simple and flexible attachment to existing Fibre Channel networks and SAN infrastructures. Near-line storage users get the benefit of low-cost, high-capacity storage without sacrificing high availability and data protection. also offers superior throughput and scalability compared with other systems typically used for near-line storage. With, organizations can reduce their overall storage costs, as well as their dependence on inflexible, proprietary systems. Rich media storage With a video-optimized architecture and dual independent 2Gb Fibre Channel interface, is the perfect complement to a Power Mac G5 video editing workstation. It provides the fast, consistent performance up to 380MB/s sustained throughput required for video post-production. In fact, delivers enough bandwidth for working in high-definition (HD) video or supporting multiple streams of uncompressed standard-definition (SD) video with real-time effects. In addition, with up to 5.6TB of online storage, makes it easy to manage multiple video tasks. Even when used for editing in uncompressed HD 1080i, this robust storage system can hold nearly 11 hours of protected RAID level 5 footage. What s more, scales in both throughput and capacity: Users need only purchase the performance level and capacity they require today, with the assurance that their investment will be protected as application and storage needs grow.

14 14 Management and Monitoring comes with RAID Admin, a powerful remote management application that dramatically simplifies setup and monitoring of multiple systems. This Java-based tool provides an intuitive interface for creating protected storage volumes, managing preferences, and monitoring storage hardware. To protect storage systems from unauthorized access, RAID Admin uses robust, multilevel password authentication. Remote management using RAID Admin The Java-based RAID Admin application works over TCP/IP, making it easy to set up, manage, and monitor Xserve RAID systems from virtually any Internetconnected computer. RAID Admin integrates with hardware to continuously monitor system activity and status. The environment management coprocessors in the RAID controllers connect to the host system via Ethernet, providing dedicated, out-of-band system management capabilities. This ensures optimum system performance and reliability, because there is no contention for bandwidth with the RAID processors or the Fibre Channel interface. Setting Up and Managing Arrays RAID Admin lets you create arrays in three easy steps. First, choose a RAID level for information about the benefits and limitations of that level. Next, click the drives you want to assign to the array. RAID Admin even gives you information about each of the drives in your system, so there s no guesswork. Any remaining drives are assigned as global hot spares for each controller. Last, choose background initialization to make the newly created array available immediately. Automatic discovery with Rendezvous Using Apple s Rendezvous technology, RAID Admin automatically discovers Xserve RAID systems on your network. This makes it easy to add them to your management window, without having to enter each IP address manually. RAID Admin provides an easy-to-use interface for creating RAID sets on the fly.

15 15 Expanding arrays Once an array is established, you can easily add more disks using RAID Admin. Expanding an array preserves the existing array while making available the capacity of the added drives. Expansion in RAID Admin works on the fly, so the expanded capacity is available in minutes. Slicing arrays To share a single RAID set across multiple servers, RAID Admin allows you to divide it into smaller segments, or slices. Each slice becomes a separate LUN, or logical unit number, so the host system can manage it as a discrete volume. Instead of creating many small arrays for individual servers, this pooling and distributing technique enables administrators to leverage the storage efficiencies of a large consolidated array. RAID Admin can slice up to eight LUNs per RAID controller, or up to 16 LUNs per system. LUN mapping RAID Admin offers advanced Fibre Channel networking features such as LUN mapping and masking. When you connect an to more than one host system on a Fibre Channel network, you can map each LUN on the RAID system to a single host and mask it from any other host. By masking arrays and slices, you avoid the possibility that more than one host will write data to an array, eliminating the risk of array corruption or data loss. An intuitive interface makes it easy to set LUN mapping, as well as other storage options. Monitoring Systems features robust self-monitoring technology that maximizes storage availability while minimizing the pressure on system administrators. RAID Admin software reports at-a-glance information about all systems on the network, with green, yellow, or red icons indicating the health of each subsystem. Administrators can easily drill down for detailed information about status and performance of each component. If operating conditions for any subsystem exceed predefined thresholds, RAID Admin can automatically notify the administrators via , pager, or capable cell phone allowing them to stay in touch with storage deployments and resolve issues without downtime or data loss.

16 16 RAID Admin software displays summary health and activity information for multiple systems. File system journaling in Mac OS X Server A robust file system journaling feature in Mac OS X and Mac OS X Server enhances the availability and fault resilience of servers and server-attached storage devices. Journaling protects the integrity of the Mac OS Extended (HFS+) file system in the event of an unplanned shutdown or power failure and maximizes uptime by expediting repairs to the affected volumes when the system restarts. Managing Volumes Administrators can use host-based volume management tools to mount storage volumes on host systems. In Mac OS X or Mac OS X Server, they can use Disk Utility to initialize arrays in Mac OS Extended or UNIX File System formats; turn on file system journaling; and set up software RAID arrays. Disk Utility makes it easy to use software RAID to create hybrid RAID levels 10, 30, and 50.

17 17 Managing Volumes with Xsan Together and Xsan provide enterprise-class storage management. Xsan, Apple s new high-performance 64-bit SAN file system for Mac OS X, enables concurrent sharing of terabytes of data over an ultrafast Fibre Channel network. Xsan is a powerful and scalable solution for enterprise storage consolidation and demanding post-production workflows. With Xsan, it is easy to configure a storage network to meet the needs of your organization. It features sophisticated volume management and monitoring tools. Xsan features Xsan Admin for setup, management of your storage systems, monitoring, and notifications. Xsan Admin provides an easy-to-use graphical user interface that enables administrators to perform complex administration tasks that would otherwise be accessible only from a command-line interface. Xsan is easy to install and configure on Mac OS X and Mac OS X Server systems. Installation and configuration can be performed locally or remotely over your local IP network. Xsan Admin includes real-time monitoring of Xsan systems and notifies the Xsan administrator of various events using or pager. Xsan Admin provides the following status information: Free space in a volume or storage pool User quota usage Graphs of CPU and network utilization Setup status notifications Status of file system processes Log file Connected clients Fibre Channel failures State of systems Xsan Admin tools can be used to map volumes to specific systems on the SAN, allowing you to limit which systems can see which volumes. Keep in mind that all Mac OS X file permissions still apply to Xsan volumes. Volume mapping simply provides an added layer of control and security.

18 18 System Architecture Fast throughput and data availability are paramount for dedicated storage systems. That s why combines leading-edge Fibre Channel, RAID, and Ultra ATA technologies in an innovative architecture designed for superior performance and reliability. Redundant, hot-swappable components and a passive midplane data path protect your digital assets from single points of failure, while independent controllers and 14 drive channels provide high-speed throughput for delivering data quickly to the host system. Architecture 1 Apple Drive Modules 6 Dual independent RAID processors 11 Redundant cooling modules 2 Independent ATA drive channels 7 Fibre Channel ports 12 Redundant power supplies 3 Drive controllers 8 Redundant environment managers 13 Cache Backup Battery Modules (optional) 4 RAID controller modules 9 Ethernet ports 5 Cache memory 10 Serial ports

19 19 Drive Technology and Capacity Instead of relying on expensive SCSI or Fibre Channel hard drives, Apple developed a high-throughput ATA to Fibre Channel storage architecture that delivers superior performance and reliability at a much lower cost. achieves its massive 5.6TB capacity with 14 hot-swappable 400GB Apple Drive Modules. The high-capacity 7200-rpm Ultra ATA drive modules provide affordable expansion and configuration flexibility as storage needs grow. Apple Drive Modules uses reliable, highperformance Apple Drive Modules with true hot-swapping capabilities. Fourteen independent drive channels The multithreaded architecture features a dedicated Ultra ATA channel for each of its 14 drive bays. Drive independence prevents data bottlenecks and maximizes throughput while enhancing availability. Because each hard drive is isolated on its own bus, a drive failure doesn t degrade the accessibility or performance of the surviving drives. In addition, independent drive channels reduce the complexity and cost of high-availability storage, since loop redundancy circuits and signal amplifiers aren t required, as they are in multidrive Fibre Channel and SCSI implementations. Apple Drive Modules Hot-plug Apple Drive Modules feature a unique handle design for fast, easy installation and a positive locking mechanism to hold them tightly in place after insertion. Sophisticated connectors called SCA II, or Single Connector Attachment II, protect the connecting pins from bending when a drive is inserted or removed. Carefully tested and qualified to ensure maximum performance and reliability, Apple Drive Modules work seamlessly with RAID Admin, Apple s innovative remote management and monitoring software for. On-drive cache Each Apple Drive Module is equipped with 8MB of disk cache to accelerate read and write operations in performance-sensitive applications such as video editing. On-drive read cache, commonly called read-ahead cache, allows the drive controller to retrieve a block of data before it is required by the host system. The RAID controller provides instructions to each drive in an array, indicating what data block is required next and allowing the individual drive controllers to queue up the data for instant availability. Similarly, on-drive cache can serve as a holding tank for write data. When this option is enabled, the RAID controller distributes data to each drive and stores it in cache allowing the drive controller to notify the RAID processor immediately that transmission was successful, also known as a committed write. This frees up the storage pipeline for other needs while the data is being written to the drive platters at maximum speed. Using on-drive write cache is inherently risky: In the event of a power failure, the cached data could be lost. For this reason, it is turned off by default in protected RAID configurations. Hot-swapping capabilities The hardware RAID controllers and Apple-designed drive carriers enable true hotswapping of Apple Drive Modules. This means a failed drive can be removed and replaced without interruption in service or loss of data. The system continues to operate while the contents of the failed drive are rebuilt on a replacement drive using redundant or parity information. (This feature is not applicable to a RAID 0 configuration, since it doesn t offer data protection.)

20 20 Monitoring of drive health hardware and remote management software work together to provide industry-leading monitoring and alerting capabilities. The RAID controller automatically reads Self-Monitoring, Analysis, and Reporting Technology (SMART) data, which allows each hard drive to report its health. This enables the operating system to warn the administrator of a prefailure condition, providing the opportunity to replace the hard drive before the failure occurs. Each drive module has two LEDs for local monitoring of drive activity and health. Passive Midplane Data Path The architecture is designed to avoid vulnerability to a single point of failure. This means that the failure of any single component can t result in a systemwide failure and loss of data availability. For highest reliability, Apple built Xserve RAID around a midplane that serves as a passive data path. The midplane is the central connector between the drives, RAID controllers, power supplies, and cooling modules. Most RAID systems depend on the midplane to relay data and instruction sets between drives, and a failure in the midplane can impair data availability. In, all data passes through the independent drive channels, which are simply held in place by the midplane. This design improves system reliability and protects the availability of stored data. RAID Controllers features two controllers that independently manage storage operations for a set of up to seven drives. Dual independent controllers allow for simultaneous storage processing. Because each controller needs to manage only seven drives, delivers outstanding performance that scales as capacity increases. These controller modules offer advanced availability and manageability features, including the environment manager, which manages RAID functions and monitors status and activity of system components. RAID processor Each controller has a powerful processor that manages all the data transfers between the hard drives and host computer. It performs the complex parity calculations required for RAID levels 3 and 5, generating parity data on the fly while managing write operations to each drive in the set. In the event of a drive failure, the RAID processor uses redundant data to rebuild its contents on a spare drive. 5 supports RAID levels 0, 1, 3, 5, and 0+1 using the RAID processor, as well as hybrid RAID levels 10, 30, and 50 by combining hardware RAID capabilities with host-based software RAID. An innovative process ensures that RAID sets are error-free and tuned for maximum throughput. When creating a RAID set, verifies the integrity of the array by checking every block on every disk for potential errors. If a bad block is discovered, it simply chooses another block that s in close proximity to the original eliminating unnecessary head movement that can result in lower performance. To maintain optimal throughput, the RAID processor uses another special technique that retrieves data on the first revolution of the RAID set. This avoids multiple retries (an activity that can hamper performance on RAID systems), while allowing Xserve RAID to maintain a nearly constant sustained throughput over the entire platter of each hard disk. Outer and inner tracks perform comparably, providing consistent, fast delivery of data to the host system. This is particularly critical in high-bandwidth applications such as HD video editing, which requires fast storage throughput for clean video capture and smooth playback.

21 21 Controller cache memory Each RAID controller is equipped with 512MB of cache memory for enhanced storage throughput. For optimal read performance, streaming data can be queued into cache, and sophisticated algorithms measure data traffic patterns and re-allocate read cache dynamically. Depending on write performance and data protection requirements, cache memory can be configured as write-back or write-through. In either case, the write cache configuration does not affect read cache settings. Write-back cache. For performance-critical applications, cache memory can accelerate write speeds using a configuration called write-back cache. In this mode, data is considered committed, or successfully received, as soon as the RAID controller writes back to the host that the information is stored in cache memory. However, as with drive cache, write-back cache is vulnerable to data loss. Since cached data is stored in SDRAM, which requires a continuous supply of power, a power outage or major system failure could result in data loss. This risk can be minimized by connecting a UPS system or using the optional Cache Backup Battery Modules. With a minimum of 72 hours of power, the battery modules preserve the contents of cache memory until system power is restored. Write-through cache. When write-through cache is enabled, the RAID controller writes data through the cache, directly to the disks, before informing the host that the write is committed. Although this may reduce performance, write-through cache is the recommended setting for protected RAID without a battery or UPS device. For high-bandwidth applications or when multiple servers are attached to, write-back cache is recommended. If a power outage occurs while using write-back cache with a UPS system, automatically reverts to write-through cache to protect the data in case of a UPS failure. Environment managers Each controller module contains a special coprocessor that monitors the enclosure environment and manages configuration of the main processor s RAID functions. This innovative environment manager simplifies management and boosts reliability by ensuring continuous feedback on the status and activity levels of system components. The environment managers integrate seamlessly with RAID Admin software and the RAID processor, providing advanced capabilities such as RAID Now for background initialization during RAID creation. Each environment manager operates on an independent bus and communicates with the host system via Ethernet. All the management and monitoring processes are handled out of band, which means Fibre Channel bandwidth is not specified for management chores. Each environment manager communicates with both RAID controllers and all hard drives. If one of the RAID environment managers fails, the other takes over and continues the monitoring and management functions to avoid any interruption in service. At the same time, it immediately notifies the administrator via of the component failure. Because the RAID environment managers connect to the host computer over Ethernet using standard Internet protocols, it s easy to connect to and monitor systems from any computer on the Internet. In addition to an Ethernet port, each environment manager has a serial port for connecting an optional UPS device, providing an extra measure of protection against power surges or electrical outages.

22 22 Fibre Channel Interconnect features dual independent 2Gb Fibre Channel ports for fast data transport between the storage system and the host computer. This industry-standard technology provides superior bandwidth, availability, and deployment flexibility over SCSI technology. To ensure interoperability, uses the latest industry-standard SCSI 3 protocol for data transfer. In addition, SFP (Small Form-factor Pluggable) connectors support low-cost copper cables, short- and long-haul SFP transceivers, and fiber-optic cables and work with industry-standard Fibre Channel switches. Apple Fibre Channel PCI-X Card connects to an Xserve or Power Mac host system using the dual-port 2Gb, 133MHz Apple Fibre Channel PCI-X Card (sold separately). Two 2.9-meter copper cables are included with the card for connecting to the two RAID controllers in the system. 400MB/s throughput Each 2Gb Fibre Channel port offers 200MB/s bandwidth for a total throughput of up to 400MB/s. 3 Fibre Channel is the only storage connectivity technology that provides guaranteed bandwidth, so the host computer receives data at the same high speed as the RAID system sends it. Superior scalability Unlike with Gigabit Ethernet or SCSI technologies, adding storage units to a Fibre Channel network doesn t lead to congestive data loss or reduced overall bandwidth. The highly scalable Fibre Channel technology can address up to 126 devices per loop, with each device experiencing a full 200MB/s throughput. In contrast, SCSI allows for a maximum of only 15 devices per channel, resulting in added expense and complexity to deploy large RAID arrays. Long-distance connectivity connects to a 2Gb Fibre Channel PCI or PCI-X card in the host computer via a thin, flexible copper or fiber-optic cable. The Fibre Channel interface also provides support for much longer distances between the storage units and the host system than is possible using SCSI cables. The Apple Fibre Channel PCI-X Card accepts shortand long-haul SFP transceivers, allowing it to use fiber-optic cables that can extend 500 meters particularly valuable for organizations using to back up or archive critical data. What s more, long-distance connectivity provides the added protection of physical separation in the event of a major disaster. High-Availability Features A modular design that features redundant components and easy serviceability makes ideal for operations where data availability is crucial. All active components are field-replaceable and most are hot-swappable. LEDs on the front and rear indicate the health of each component: green means OK, yellow indicates warning, and red signals failure. In the event of a component failure, the remote monitoring system notifies the administrator via , allowing repairs to be accomplished in seconds usually without shutting down the system. Redundant components The environment managers monitor the enclosure and the status of system components. If one of the power supplies fails, the other takes over and powers the system alone until the failed module is replaced. The environment managers themselves are redundant: Both monitor the entire enclosure and record status information on all components, enabling automatic adjustments and remote notifications as needed. If an environment manager fails, the other one takes charge of monitoring the system.

23 23 UPS support A single power supply can sustain the system in the event of a power outage or electrical surge. Each RAID controller has its own DB-9 serial port, allowing to connect to and monitor up to two UPS sources. When the system detects that input power has been switched to a UPS source, it changes the cache mode from high-performance write-back to safer write-through cache protecting data transactions should the UPS fail. If the UPS system is capable of reporting a low power level, can alert the administrator of the condition, permitting a manual shutdown before the power runs out. Cache Backup Battery Modules With optional Cache Backup Battery Modules in, data transactions in the RAID controller cache are protected for more than 72 hours after an input power failure. Once power is restored, writes the transactions and begins recharging the batteries. If battery power is low, the system remains in write-through cache mode until the battery charge exceeds 50 percent, when it returns to write-back mode. Hot sparing For each RAID controller, any drives not assigned to an array are automatically used as global hot spares. If a drive fails, the RAID controller rebuilds its data on the spare drive without requiring intervention by the administrator. The rebuild operation occurs in the background while the controller processes normal host reads and writes so service continues uninterrupted. 5 To promote the best mix of performance and rebuild speed, the rebuild rate varies with the amount of traffic, or fabric load, on the RAID controller. As soon as the administrator replaces the failed drive, configures it as a new global hot spare for the array. Easy serviceability Power supplies, cooling modules, RAID controller modules, and hard drives can be removed and replaced in seconds without tools. These components are all hotswappable, which means they can be replaced without interrupting data availability. In addition, has a shutdown feature that allows for planned maintenance without running down the cache backup batteries. This feature can also be beneficial if is stored for long periods of time.

24 24 Service, Support, and Training Options Every comes with a one-year limited warranty and 90 days of up-andrunning telephone support. In addition, the AppleCare website publishes in-depth product information, training on hardware and software installation and configuration, and technical resources, including the AppleCare Knowledge Base, discussions, and downloadable software on Apple s Featured Software site. For critical data storage deployments, Apple also offers a comprehensive range of service and support options for Xserve,, and Mac OS X Server. For more information about these AppleCare products, see AppleCare Premium Service and Support Plan This server-class support product provides up to three years of up-and-running telephone and support and onsite hardware service. Apple technical support experts are available 24 hours a day to help you determine whether you re experiencing a hardware failure or a RAID Admin configuration issue. In either case, Apple will work to get systems up and running quickly. The AppleCare Premium Service and Support Plan delivers up-and-running telephone and support within 30 minutes 24 hours a day, seven days a week. The hardware repair coverage provides onsite response within four hours during business hours and next-day onsite response when you contact Apple after business hours (terms apply). 7 For added peace of mind, you ll have the assurance that Apple-authorized technicians will perform repairs using genuine Apple parts. The AppleCare Premium Service and Support Plan can be purchased at any time while is still under its original one-year warranty. However, since coverage ends three years after the hardware purchase date, you ll get maximum advantage when you make both purchases at the same time. AppleCare Service Parts Kit is designed for quick and easy swapping of crucial parts; no special tools or training certifications are needed. AppleCare Service Parts Kits let system administrators keep key components handy to address the most common hardware failures. Each kit has an Apple Drive Module, a power supply, a cooling module, and a RAID controller module. When the AppleCare Premium Service and Support Plan is combined with an AppleCare Service Parts Kit, technical support experts can often help troubleshoot and fix systems right over the phone day or night eliminating the need for an onsite technician.